Ballasting system for fluorescent lamps

Abstract

A ballasting system for powering an array of flourescent lamp assemblies, as in a sun tanning apparatus, comprises an electronic frequency converter adapted to convert ordinary 60 Hz power line voltage into two non-current-limited high frequency outputs: a first output of 400 Volt/30 kHz sinusoidal voltage provided between a first pair of distribution conductors, and a second output of 50 Volt/30 kHz sinusoidal voltage provided between a second pair of distribution conductors. Each lamp assembly comprises two mutually parallel-disposed series-connected fluorescent lamps. The 50 Volt/30 kHz voltage is provided to the one end of this assembly and is used by way of an isolation transformer means to provide cathode heating power for the two lamp cathodes located near that end. The 400 Volt/30 kHz, voltage is provided to the other end of the assembly and, in addition to providing cathode heating power by way of isolation transformer means, provides a voltage of magnitude directly suitable for starting and running the two series-connected lamps by way of a simple inductive or capacitive reactance ballast. Every other lamp assembly is ballasted with an inductive reactance ballast; and every alternate other lamp assembly is ballasted with a capacitive reactance ballast. That way, the net load represented by any even number of lamp assemblies will be substantially resistive.

I claim: 
     
       1. A system for providing photic radiation, said system being adapted to be powered from the line voltage of an ordinary electric utility power line and comprising: a plurality of fluorescent lamp assemblies, each such assembly having: (i) a fluorescent lamp with a first and a second cathode, (ii) a first input terminal means located adjacent said first cathode, (iii) a second input terminal means located adjacent said second cathode, (iv) first power transfer means connected between said first input terminal means and said first cathode, and operative to permit the transfer of electrical power therebetween, said first power transfer means including first transformer means and current-limiting means, and (v) second power transfer means connected between said second input terminal means and said second cathode, and operative to permit electric power transfer therebetween, said second power transfer means including second transformer means;   power conditioning means connected with said power line and operable to provide a first AC voltage at a first output terminal means and a second AC voltage at a second output terminal means;   first distribution conductor means connected with said first output terminal means and operative to provide said first AC voltage to the first input terminal means of each fluorescent lamp assembly; and   second distribution conductor means connected with said second output terminal means and operative to provide said second AC voltage to the second input terminal means of each fluorescent lamp assembly.   
     
     
       2. The system of claim 1 wherein: (i) said fluorescent lamp is an essentially straight tubular entity, (ii) the fluorescent lamp in each lamp assembly is substantially parallel with the fluorescent lamp in any of the other lamp assemblies, and (iii) said first distribution conductor means and said second distribution conductor means are both oriented in a substantially perpendicular manner with respect to said fluorescent lamps, whereby no conductor means are required to run parallel with any of the fluorescent lamps. 
     
     
       3. The system of claim 1 wherein said AC voltages are of essentially sinusoidal waveform and fundamental frequency substantially higher than that of said line voltage. 
     
     
       4. The system of claim 1 wherein each of said fluorescent lamp assemblies comprises two series-connected fluorescent lamps. 
     
     
       5. A system for providing photic radiation, said system being adapted to be powered from the line voltage of an ordinary electric utility power line and comprising: a plurality of fluorescent lamp assemblies, each such assembly having: (i) a first substantially straight and tubular fluorescent lamp with a first and a second cathode, (ii) a second substantially straight and tubular fluorescent lamp with a first and a second cathode, said second lamp being positioned such as to have its first and second cathode adjacent the first and input terminal means located adjacent said first cathodes, (iv) a second input terminal means located adjacent said second cathodes, (v) first power transfer means connected between said first input terminal means and said first cathodes, and operative to permit the transfer of electrical power therebetween, said first power transfer means including first transformer means and current-limiting means, and (vi) second power transfer means connected between said second input terminal means and said second cathode, and operative to permit electric power transfer therebetween, said second power transfer means including second transformer means;   power conditioning means connected with said power line and operable to provide a first AC voltage at a first output terminal means and a second AC voltage at a second output terminal means;   first distribution conductor means connected with said first output terminal means and operative to provide said first AC voltage to the first input terminal means of each fluorescent lamp assembly; and   second distribution conductor means connected with said second output terminal means and operative to provide said second AC voltage to the second input terminal means of each fluorescent lamp assembly.   
     
     
       6. The system of claim 5 wherein, within each lamp assembly, said second cathodes are electrically connected together. 
     
     
       7. The system of claim 6 wherein said second distribution conductor means has an electric conductor and wherein said cathodes are connected with said electric conductor by way of a capacitor means. 
     
     
       8. The system of claim 5 wherein: (i) said power conditioning means comprises frequency conversion means, and (ii) the frequency of said first AC voltage is substantially higher than that of said line voltage. 
     
     
       9. A fluorescent lamp assembly requiring for proper operation to be connected with both a first and a second distribution conductor means, each distribution conductor means including at least two electrical conductors between which there exists a voltage differential, the assembly comprising: a first substantially straight and tubular fluorescent lamp having a first and a second cathode;   a second substantially straight and tubular fluorescent lamp also having a first and a second cathode, said second lamp being positioned in such manner as to have its first and second cathode adjacent the first and second cathode of said first lamp, respectively;   first input terminal means located adjacent said first cathodes and adapted to connect with said first distribution conductor means;   second input terminal means located adjacent said second cathodes and adapted to connect with said second distribution conductor means;   first power transfer means connected between said first input terminal means and said first cathodes, and operative to permit the transfer of electrical power therebetween, said first power transfer means including first transformer means and current-limiting means; and   second power transfer means connected between said second input terminal means and said second cathodes, and operative to permit electric power transfer therebetween, said second power transfer means including second transformer means.